The present invention relates to an electro-optical display containing an electrochromic material which manifests reversible variations in their light absorption properties upon application of properly controlled voltage or current. This display is referred to as an "electrochromic display (ECD)" hereinafter.
The present invention relates, more particularly, to an electrochromic display cell which employs a thin film of amorphous tungsten (WO.sub.3) as an electrochromic material, and a liquid electrolyte as an ion source.